Trivia: The call sign for the mobile command center is SHIELD 616. Earth-616 is the name for the primary universe in Marvel comics.
All-New Halloween Spooktacular! - S1-E6
Trivia: When Pietro says he'll help the twins maximise their candy acquisition, one twin says "Kick-ass!" and Wanda repeats to herself "kick-ass." Both Aaron Taylor-Johnson, who played Pietro in Avengers: Age of Ultron, and Evan Peters, who plays "Pietro" in WandaVision and the recent X-Men films, both starred in Kick-Ass.
Trivia: Only mentioned in one episode early in the series, Steve Austin's least-referenced superhuman power was his ability to hold his breath for extraordinary lengths of time. Steve's phenomenal breath-holding ability was due to the fact that, even though he had two normal lungs, he had a much smaller circulatory system than a normal human being. Also, the Steve Austin in Martin Caidin's original book, "Cyborg," had an entire array of weapons, flares, communications gear, retractable swim fins, and scuba tanks built into his bionic body.
Trivia: When the detective is first showing Zimmerman the sketches, when Zimmerman comments that the pictures are brilliant the sketch is of an Unas, a creature from Stargate SG1, starring Amanda Tapping, it also appears in the top right when Zimmerman shows the sketches to Dr. Magnus. (00:04:00 - 00:04:45)
Clone Cadets - S3-E1
Trivia: Commander Colt watches Domino Squad do their test and says, "Start The Citadel challenge, version THX, variable 1138," which is a reference to THX 1138, another film by George Lucas.
Trivia: When Kyle is knocked into the airfield by Siniestro, he crashes into a Sabre jet. As he recovers, we read the pilot's name as Col. Hal Jordan. This is the name of the second, Silver Age Green Lantern.
Trivia: Although Laurel is a couple of years older than Sara, Katie Cassidy is only about a month older than Caity Lotz.
Trivia: Stan Lee has a cameo in this episode as the man having his shoes polished next to Stark and Jarvis.
Trivia: Paul says to Dr Cruz that they will take a trip to La Boheme. That is an homage to Paul's role on Rent, where he sings La Vie Boheme.
Trivia: Alan Ritchson, who plays Hawk, also played Aquaman in the Smallville TV show.
Not All Men - S1-E7
Trivia: When Taissa leaves work and sees an angry man in his car repeatedly trying to jam his straw into his drink, the logo on the cup is the Busy Bee Cafe logo. The Busy Bee cafe was seen in the original Twilight Zone episode Nick of Time with William Shatner.
Trivia: Simon Pegg's extended cameo as Hughie's father is a specific nod to the comics - the look of "Wee Hughie" in the original comics was based on Simon Pegg. Artist Darick Robertson said "it was important to capture an innocence but tough determination in Hughie. Two things that seemed to contradict each other and somehow in early sketches he kept looking too old. When I saw Simon Pegg in Spaced I thought he captured that balance perfectly." Pegg knew he was too old to play the character himself, but was happy to play his father.
Behold the Negative Zone - S1-E12
Trivia: When Blastaar comes through the Negative Zone into the Earth dimension, Thing remarks that Blastaar makes him look like Brian Austin Green. Brian Austin Green was the voice of Human Torch for the first season of this show. (00:11:18)
Tolerance Is Extinction - Pt 2 - S1-E9
Trivia: When Cable scoffs at the uniform Cyclops gives him to wear, Cyclops asks if he was expecting black leather. This is a reference to the first X-Men film, when Wolverine scoffed at the X-Men's black leather uniforms, only for Cyclops to ask him if he preferred yellow spandex instead.
The Great Vegetable Rebellion - S3-E23
Trivia: Due to their uncontrollable laughter during filming of the infamous "Vegetable Rebellion" episode, Guy Williams and June Lockhart were written out of the next two episodes.